The symbol used to add a grammar that will get appended to this grammar.
The rest property can be the id of a language in languages.
If that grammar doesn't yet exist, the rest property persists, and the
the rest grammar will be appended once it exists.
The symbol used to add a grammar that will get appended to this grammar.
The
restproperty can be the id of a language in languages. If that grammar doesn't yet exist, therestproperty persists, and the the rest grammar will be appended once it exists.